Glove molding apparatus

ABSTRACT

A method and apparatus provided for manufacturing elastomer gloves having percentage elongation of at least 300%. In order to prevent excess deposits of the polymer latex in the areas of the tips of the fingers and the webs between the fingers when the hand-shaped molds are coated, by dipping, with the polymer, the surfaces of the mold in these areas are formed as non-rounded, non-horizontal inclined surfaces which join at an apex and define an included angle therebetween. This arrangement prevents the pooling of the polymer latex in the areas in question, this pooling being the cause of the excess deposits and being characteristic of prior molds of this general type. In order to provide sufficient coagulant around the sharp corners formed in the areas of the tips of the fingers and the webs between the fingers so as to provide sufficient coating in those areas, it is necessary to use a heated mold and to provide sufficient dwell time and withdrawal time for the mold from the coating baths during the process.

This is a division of application Ser. No. 125,925 filed Feb. 29, 1980pending 140.

FIELD OF THE INVENTION

The present invention relates to a method and apparatus for moldingelastomer gloves.

BACKGROUND OF THE INVENTION

In prior U.S. Pat. Nos. 3,856,561; 3,967,014; 3,919,442 and 4,027,060,there is described a method of manufacturing gloves, such as surgicalgloves wherein a synthetic resin slip coating is provided as inner andouter layers on the rubber elastomer layer. This provides a surgicalglove with a slip coating so that the surgeon no longer needs to usepowder in order to put on and remove the gloves.

A substantial difficulty has arisen, however, in the use of the processdescribed in the above referenced patents. It has been found that thepolymer latex tends to form small pools of excess polymer latex oncertain surfaces of the glove mold. These pools, upon drying, leaveexcess deposits of the polymer latex in these areas. More specifically,the areas of the molds where these problems occur are the tips of thefingers and the interfinger webs of the glove mold. These excessdeposits formed by the use of the conventional surgical glove molds havea poor adhesion to the underlying rubber latex. These polymer depositshave a tendency to shed into the surgical wound because of the pooradhesion. Such shedding is obviously undesirable. It is not possible toremove the excess polymer latex from the glove without ruining theglove.

Attempts have been made to solve this problem by withdrawing the moldfrom the elastomer tank with the fingers being withdrawn last. However,in using this procedure, it has been found that webbing occurs betweenthe fingers and that when the webs break an excess of the polymer latexoccurs on the surface of the glove.

SUMMARY OF THE INVENTION

The present invention is in part based on the inventive appreciationthat as the finger tips and webs of the coated mold emerge from thepolymer solution in the manufacturing process described above, a smallsection of all of the finger tips and a section of all of the websbetween the finger are horizontal as they emerge from the surface of thepolymer bath. It has been determined that it is these sections whichhave the excess deposits referred to above. Moreover, the deposits inquestion are exclusively limited to these horizontal surfaces.

According to the invention, non-rounded, angled surfaces are provided ineach of the areas which are prone to excess deposits of polymer, i.e.,at the tips of the fingers and the connecting webs between the fingers.In a preferred embodiment, an included angle is introduced at thelocations in question so that all horizontal surfaces are eliminated andthe formation of pools of excess polymer is done away with. In aspecific exemplary embodiment, the surfaces form an included angle of 90degrees, i.e. each surface forms an angle of 45 degrees with thevertical. However, the included angle can, of course, be varied and anincluded angle of 120 degrees (a 60 degree slope with respect to thevertical) or even 150 degrees (a 75 degree slope with respect to thevertical) might be satisfactory. Of course, the closer the surfacesapproach the horizontal the greater the probability of poolingoccurring. On the other hand, as the included angle is increased, andthus the slope of the angled surfaces approaches 90 degrees, theprobability of pooling decreases. However, the glove must be worn by thehuman hand and, moreover, there may be difficulties in the fabricationof the mold for such angles since thin molded walls are preferably used,and this would create problems in providing very steep surfaces, i.e.,very small angles with respect to the vertical.

While it was found that by eliminating horizontal surfaces in the mannerdescribed, it was possible to avoid pooling problems in connection withlaying down the polymer coating, the sharp corners on the mold tended toprevent the formation of a sufficient elastomer layer in that area. Thisproblem was solved by modifying the method of manufacture of the gloveby heating the mold to a temperature of about 140° F. and providing adwell time and withdrawal time from the coagulant and elastomer bathswhich permits the formation of a uniform elastomer layer even in thefinger tip and web areas where sharp corners exist.

Other features and advantages of the invention will be set forth in, orapparent from, the detailed description of the preferred embodimentdescribed below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a molding apparatus for making surgicalgloves, showing the glove molds for the individual gloves as they emergefrom the polymer or rubber latex baths;

FIGS. 2 and 3 are front and side elevational views, respectively, of anindividual glove mold incorporating the present invention; and

FIG. 4 is a perspective view of a detail of one finger of the mold ofFIGS. 2 and 3, broken away to show the construction thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 2 and 4, an exemplary glove mold constructed inaccordance with the present invention is shown, the illustrated moldcorresponding to mold 14 of FIG. 1. As discussed above, pooling of thecoating polymer at certain locations on the mold results in excessdeposits of this polymer at various locations on the glove produced.These locations, which are nine in number, are identified in FIG. 2(and, in part, in FIG. 3) by the leters A to I, and, as shown, are thetips of the fingers (A to E) and the webs between fingers (F,G,H,I).According to the present invention, the surfaces of the mold of theselocations are formed as nonrounded, angled (non-horizontal) surfaces andin the illustrated embodiment, as a pair of surfaces defining anincluded angle therebetween. Thus, considering finger tip B as typical,the surfaces 20 and 22 forming this tip (see FIG. 3) are inclined andjoin at an apex 24 to define an included angle therebetween. Similarly,the web G between the fingers having tips D and C is formed by a pair ofinclined surfaces, one of which, denoted 26, is shown.

In the illustrated embodiment, the included angle appears to be about 60degrees or 70 degrees (each surface forming an angle of 30 degrees to 35degrees with the vertical) and actual testing has been performed with anincluded angle of 90 degrees. However, as discussed above, includedangles up to 150 degrees or more could be acceptable. Further, as wasalso discussed, a small included angle could be used although while theformation of deposits would be further decreased, there are practicallimits from both an appearance and a manufacturing standpoint. In thislatter regard, as shown in FIG. 4, the mold is preferably constructed asa thin shell, preferably of porcelain or the like. Thus, a more or lessarbitrary range of about 50 degrees or less to about 150 degrees iscontemplated.

Referring to the FIG. 1, a molding apparatus is shown which includes atank 10 having a bath or solution 11 of a suitable polymer therein. Forpurposes of illustration, a polymer latex of the type disclosed in theabove referenced prior art patents will be considered although it isclear that other polymers can be used. A mold device 12 comprises a pairof glove molds 14 and 16 for molding a pair of gloves. Molds 14 and 16are preferably fabricated of a thin walled porcelain and are mounted onrespective ones of a pair of base mounts 14a and 16a which are connectedby respective rods 14b and 16b to a central mounting or carrying shaft18.

In use of the molding apparatus of FIG. 1, glove molds 14, 16 arecompletely submerged in the polymer latex bath 11 contained in tank 10,the mold device 12 which supports glove molds 14 and 16 being loweredinto bath 11 by means of mounting shaft 18. The molds are heatedinternally to a temperature of about 140° F. The mold is allowed toremain in the tank for a dwell time of about five minutes. The polymerlatex solution 11 thus surrounds molds 14, 16 so as to form a coatingthereon and thereafter the entire mold device is slowly withdrawn fromtank 10. Withdrawal time of the mold from the bath should be about tento twelve minutes. In FIG. 1, the glove molds 14, 16 are shown in thepositions they assume just after the tips of the molds emerge from bath11. The shaft 18 is, of course, continuously raised so that eventuallyall of the molds 14, 16 are completely removed from the bath.

Following the deposition of the polymer latex as above described, themold with polymer coating is then dipped in coagulant of the typedescribed in the above referenced patents. The mold is dipped rapidlyand is brought out after no dwell time over a period of about 30seconds. Subsequently, a rubber latex coating is applied. The mold iscooled to 100° F. and is dipped in the rubber latex bath which is at atemperature of approximately 70° F. The mold is inserted in the bath ata rate of approximately 1.2 inches per second and is permitted to remainfully immersed for a period of 8 to 10 seconds. The mold is thenwithdrawn from the bath at the same rate as the insertion rate. Theglove mold with the inner polymer coating and outer rubber latex coatingis then given a final polymer latex coating. The mold is inserted in thepolymer bath so as to be fully immersed within approximately threeseconds and the mold temperature is then raised to about 140° F. Themold is permitted to remain fully immersed for a period of five minutesand then is slowly withdrawn over a period of ten to twelve minutes.

By the above described process, a surgical glove is produced having arubber latex layer with inner and outer polymer coatings. By eliminatinghorizontal surfaces on the mold pooling of the polymer is avoided and byuse of a heated mold and dwell and withdrawal periods as specifiedherein a sufficient coating of polymer and elastomer even on pointedsurfaces of the mold is assured.

Although the invention has been described in relation to an exemplaryembodiment thereof, it will be understood by those skilled in the artthat variations and modifications can be effected in this exemplaryembodiment without departing from the scope and spirit of the invention.

I claim:
 1. A molding device for molding gloves having a percentageelongation of at least 300%, said device including a tank containing apolymer, a pair of glove molds supported on a suppot arrangement adaptedto be submerged in said tank so as to provide a coating of said polymeron said molds, each of said glove molds comprising a handshaped moldmember including separate, spaced fingers and the tips of the fingersand the spaces between the fingers comprising non-rounded,non-horizontal inclined surfaces which are joined at an apex and definean included angle therebetween.
 2. An apparatus as claimed in claim 1wherein said included angle is between about 50 and 150 degrees.
 3. Anapparatus as claimed in claim 2 wherein said included angle is between60 degrees and 90 degrees.